# Full text of "The Flow Of Gases In Furnaces"

## See other formats

```54

APPLICATION OF THE  LAWS OF  HYDRAULICS

NORMAL VELOCITY OF GAS FLOW UNDER INVERTED WEIR
B=2 m 00 = width of furnace, corresponding to length of weir.

ht =
1 mOO
Om 75
Om 50
0 m 30

A =
3.28
3.37
3.46
3.54

t
Velocity", Meters per Second = v

500°
3.764
3.131
2.462
1.839

600°
4.123
3.428
2.691
2.014

700°
4.454
3.704
2.823
2.176

800°
4.761
3.959
3.108
2.326

900°
5.050
4.199
3.296
. 2.467

1000°
5.323
4.427
3.474
2.600

1100°
5.584
4.643
3.677
2.727

1200°
5.832
4.849
3.806
2.849

1300°
6.069
5.047
3.961
2.965

1400°
6.299
5.238
4.140
3.077

1500°
6.520
5.422
4.255
3.185

1600°
6.736
5.599
4.394
3.289

1700°
6.941
5.772
4.530
3.390

1800°
7.142
5.939
4.661
3.489

Qt =
2.00/>
1.50*
l.OOw
0.600

These tables shows that, for a horizontal roof, the velocity of
the hot gases ordinarily varies from 1 m 94 to 8 m 29 per second.
And, as in reverberatory furnaces, it is necessary that the hot gases
should remain in the furnace a sufficient time to give up heat to
the material being heated, in certain industrial heating applications
there will be found to be a relationship between the circulation
velocity of the hot gases and the application. But it is evident,
on the other hand, that there should be no necessity for accelerat-
ing the velocity of the hot gases, because this would lead to the
construction of extremely long furnaces.
A number of attempts have been made to determine the time
which is required for the transmission of the heat in the hot gases to
the materials being heated and to the walls of the furnace. Observa-
tions and computations have led to the establishment of two limits```